On Tuesday, 7 January 2014 at 00:54:10 UTC, bearophile wrote:
Meta:
Why not just return arr.dup instead? You're returning a slice
of a stack-allocated array, so of course you shouldn't write
code like this.
In certain critical code paths heap allocations are evil
(perhaps even if your generational GC has a stack-like nursery,
that currently the D GC doesn't have) :-) And you also want to
minimize copies and initializations.
Bye,
bearophile
Wouldn't it be better to simply allocate on the stack directly in
the calling function? Or if that is not a possibility use a
region allocator or even a ScopeStack allocator? It's basically
just a pointer bump so it should be fast.
So it would translate to something like this:
int[] foo(Allocator)(ref Allocator allocator)
{
auto arr = allocator.allocate!(int[])(5);
foreach(i, ref elem; arr)
elem = i;
return arr;
}
